Footwear with breathable sole

ABSTRACT

Footwear having a ventilated sole system to cool the foot is provided. The footwear includes a generally horizontal sole having an outer sole and an insole providing a surface adjacent the foot. The footwear also includes an air flow pump positioned between the outer sole and the insole. The air flow pump includes a generally horizontal tubular pump element extending generally transverse of the footwear from a medial side of the sole to a lateral side of the sole. The pump element defines an interior volume and has opposite ends open to ambient air. The pump element also has a plurality of holes therein providing fluid communication between the interior volume and the surface adjacent the foot. The pump element is resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff causing ambient air to flow through the holes in the pump elements to cool the foot.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 60/417,895, filed Oct. 11, 2002, titled FOOTWEAR WITH BREATHABLE SOLE.

BACKGROUND OF THE INVENTION

[0002] While shoes provide protection and cushioning, they also tend to trap heat and inhibit circulation of air around the foot. As the temperature of the foot rises, the natural cooling system of the body triggers sweat glands in the skin to release sweat to cool the foot. The warm, moist environment in the shoe promotes the growth of a normal flora of bacteria, yeast and fungus found around the foot and the added moisture from sweaty feet causes the normal flora to multiply more rapidly, leading to foot odor. Typical synthetic shoe uppers and liners commonly used compound this problem because they are made of material that doesn't allow air to pass through. The air has a cooling effect that helps maintain a comfortable foot temperature. Reducing the amount of air circulating around the foot causes the foot temperature to rise and leads to sweaty feet and foot odor

[0003] Attempts have been made to address this issue by making at least a portion of the shoe upper out of a “breathable” material (i.e., air permeable material) or by providing perforations in the shoe upper. While these measures are helpful, their effectiveness leaves much to be desired. One reason is that there is not much to compel air to actually flow through the breathable material or perforations. Additionally, about 60 percent of the pores on the foot are on the bottom or sole of the foot.

[0004] Air circulation systems including a pumping device contained within the sole of the footwear have been attempted to address this problem by bringing in additional air to cool the foot. As the wearer steps down on the footwear, the pumping device is compressed forcing air contained therein to circulate over the foot through openings in the insole. When the wearer's weight is lifted from the footwear, the pumping device expands to refill with air. However, conventional air circulation systems often fail to provide the desired balance between resiliency, flexibility, durability, visual aesthetics, and cost.

SUMMARY OF THE INVENTION

[0005] Among the several objects of this invention may be noted the provision of footwear having a sole (e.g., outer sole, midsole and/or insole) which provides for the forced flow of ambient air to the foot inside the footwear to cool it; the provision of such footwear which provides good foot support while cushioning the foot; the provision of such footwear which is economical to manufacture; and the provision of such footwear which is attractive in appearance.

[0006] In general, footwear of the present invention comprises a generally horizontal sole having one or more air flow pumps therein. Each air flow pump comprises a generally horizontal tubular pump element defining an interior volume and having opposite ends open to ambient air. Holes along the pump element provide fluid communication between the interior volume of the element and a surface of the footwear adjacent a foot in the footwear. Each pump element is resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff during walking or running. This resilient compression and expansion causes ambient air to flow through the holes in the one or more pump elements to cool the foot.

[0007] In another aspect, the invention is directed to footwear having a ventilated sole system to cool a foot in the footwear. The footwear includes a generally horizontal sole having an outer sole and an insole providing a surface adjacent the foot. The footwear also includes an air flow pump positioned between the outer sole and the insole. The air flow pump includes a generally horizontal tubular pump element extending generally transverse of the footwear from a medial side of the sole to a lateral side of the sole. The pump element defines an interior volume and has opposite ends open to ambient air. The pump element also has a plurality of holes therein providing fluid communication between the interior volume and the surface adjacent the foot. The pump element is resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff, the resilient compression and expansion causing ambient air to flow through the holes in the pump elements to cool the foot.

[0008] Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a side elevation of footwear having a ventilated sole system in accordance with this invention;

[0010]FIG. 2 is an exploded view of the sole of the footwear of FIG. 1;

[0011]FIG. 3 is an exploded view of the midsole of the footwear with the liner removed illustrating the ventilated sole system;

[0012]FIG. 4 is a perspective view of the midsole with parts broken away to show detail of the ventilation system;

[0013]FIG. 5 is an enlarged perspective view of the midsole similar to FIG. 4;

[0014]FIG. 6 is a perspective view of an embodiment of an air flow pump of the ventilated sole system;

[0015]FIG. 7 is a perspective view of another embodiment of an air flow pump of the ventilated sole system; and

[0016]FIG. 8 is a perspective view of another embodiment of an air flow pump of the ventilated sole system having a waterproof barrier.

[0017] Corresponding parts are indicated by corresponding reference numbers throughout the drawings.

DETAILED DESCRIPTION

[0018] Referring to FIGS. 1 and 2 of the drawings, footwear incorporating the construction of the present invention is indicated in its entirety by the reference numeral 1. In the embodiment shown, the footwear 1 comprises a sole, indicated generally at 3, and a shoe upper 5 (shown in phantom), such as the upper of a running shoe, but it will be understood that the teachings of the present invention are applicable to other types of footwear, such as boots, sandals, dress shoes, etc. In one embodiment, the sole comprises multiple parts, including a lower outer sole 7, a midsole 9 above the outer sole, and an insole 11 (e.g., a liner or sock) above the midsole. The sole 3 also has heel, arch, forefoot and toe sections indicated at 17, 19, 21 and 23, respectively. Preferably, the sole 3 is contoured to provide support for the foot in accordance with the teachings of co-assigned U.S. Pat. No. 4,272,899 entitled “FOOTWEAR”, which is incorporated by reference in a manner consistent with this disclosure.

[0019] The outer sole 7 is of a durable material, such as rubber, for example, having a suitable tread pattern. The insole 11 is of a suitable insole material (e.g., cotton, felt, nylon, EVA, poron (foams) or a “Gor-Tex” material) and configured to engage the foot of the wearer. Except as further described below, the shoe upper 5, outer sole 7 and insole 11 may be of conventional construction understood by those of ordinary skill in the art. Accordingly, additional details of construction and operation of the upper 5, outer sole 7 and insole 11 will not be described herein.

[0020] The midsole 9 is fabricated from a suitable compressible and resilient material or materials to provide cushioning to the foot while walking or running. In one embodiment, the midsole 9 is fabricated in accordance with the teachings of co-assigned U.S. Pat. No. 5,787,610 entitled “FOOTWEAR” and U.S. Pat. No. 5,964,046 entitled “FOOTWEAR”, both of which are incorporated by reference in a manner consistent with this disclosure.

[0021] Referring now to FIGS. 3-5, the midsole 9 is constructed with one or more recesses therein, suitably a first recess 27 in the arch section 19, and a second recess 29 in the forefoot section 21 for receiving a corresponding number of air flow pumps, each generally designated 31. In the embodiment described above, the air flow pumps 31 are located in the arch section 19 and forefoot section 21 of the midsole 9, but it will be understood that they may be located in other areas of the sole, including the heel section 17 and the toe section 23, or any combination of sections. In the embodiment shown, each air flow pump 31 comprises a plurality of elongate generally horizontal tubular pump elements 33 mounted on a substrate 35 that overlies the outer sole 7. The pump elements 33 are arranged to extend generally transversely of the sole 3 from a medial side 36 to a lateral side 37 of the sole. Alternatively, the pump elements 33 can extend longitudinally of the sole or in some other direction. Preferably, the pump elements 33 and substrate 35 are molded as an integral unit, but this is not essential; in fact, the substrate can be eliminated entirely, if desired. Alternatively, the pump elements 33 can be molded as part of the midsole 9. Further, the pump elements 33 may be formed as part of a sole 3 which does not include a midsole.

[0022] As best seen in FIGS. 6 and 7, each pump element 33 defines an interior volume 38 and has opposite open ends 39. The pump elements 33 may have various compressible shapes and forms. For example, the pump elements 33 in FIG. 6 are accordion-shaped in vertical cross section, and the pump elements 33 in FIG. 7 are circular in vertical cross section. Other shapes are possible. Optionally, the end portions of the elongate pump elements 33 may be enlarged to increase the flow of air through the pump elements to the foot. The open ends 39 are in registration with holes 45 (FIG. 3) in the sides 36, 37 of the midsole 9 so that the open ends 39 of the pump elements 33 are open to ambient air. The holes 45 may have an ornamental shape (e.g., star shaped as shown in FIG. 1 or circular as shown in FIG. 3), if desired, to enhance the appearance of the footwear 1. The pump elements 33 are fabricated from a resiliently compressible material such as polyurethane, TPR, PVC or EVA or other suitable material having a Type C (commonly referred to as “Shore C scale”) durometer hardness measured in accordance with American Society of Testing and Materials (ASTM) standard D 2240-97 in the range of about 45-65, for example.

[0023] A row of holes 47 is provided along the top of each pump element 33. The recesses 27, 29 in the midsole 9 containing the air flow pumps 31 are covered by a suitable liner 51 having openings 53 therein (see FIG. 2). The openings 53 are suitably in communication with the holes 47 in the pump elements 33 such that air can pass out of holes 47 and through openings 53. The insole 11 (FIG. 2) is made of a breathable material or also may have perforations. The arrangement is such that each pump element 33 is resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff during walking or running. This repeated compression and expansion causes ambient air to be pumped into the open ends 39 of the pump elements 33 and to flow up through the holes 47 in the pump elements 33, through the holes 53 in the liner 51 and then through the insole 11 to provide ventilation to the foot. The ventilation cools the foot, thus decreasing the amount of perspiration produced and reducing foot odor.

[0024] Referring now to FIG. 8, in one embodiment, the open ends 39 of the pump elements 33 are covered by appropriate moister barriers 60. In one embodiment, the barriers 60 are of a suitable material pervious to the inflow of air but substantially impervious to the flow of water, such as a polytetrafluoroethylene material sold under the “Gor-Tex” trademark owned by W. L. Gore and Associates of Newark, Del., to prevent the flow of water into the pump elements 33. Alternately, the barriers 60 can be valves having multiple movable flaps that open and close with pressure on the sole 3 without departing from the scope of the invention. Such barriers 60 can have flaps similar in design to flaps in venous valves that permit flow in one direction when in an open position and prevent flow in a closed or sealed position. Such a barrier 60 substantially prevents backflow thus creating a vacuum in the pump element 33 to recapture air from around the foot. Additionally, the barrier 60 can be a strip of suitable material (not shown) extending along outer sides of the midsole 9 covering the open ends 39 of the pump elements 33.

[0025] When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0026] As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 

What is claimed is:
 1. Footwear comprising a generally horizontal sole having at least one air flow pumps therein, each air flow pump comprising a generally horizontal tubular pump element defining an interior volume and having opposite ends open to ambient air, and holes in the pump element providing fluid communication between said interior volume and a surface of the footwear adjacent a foot in the footwear, each pump element being resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff during walking or running, said resilient compression and expansion causing ambient air to flow through the holes in said one or more pump elements to cool the foot.
 2. Footwear as set forth in claim 1 wherein said at least one air flow pump comprises a plurality of tubular pump elements having ends open to ambient air.
 3. Footwear as set forth in claim 2 wherein said plurality of pump elements extend generally transverse of the footwear from a medial side of the sole to a lateral side of the sole.
 4. Footwear as set forth in claim 2 wherein the open ends of the pump elements are covered with a barrier pervious to the flow of air but substantially impervious to the flow of water.
 5. Footwear as set forth in claim 2 wherein the open ends of the pump elements are covered with a valve having movable flaps making the valve substantially impervious to the flow of water when the flaps are in a closed position.
 6. Footwear as set forth in claim 2 wherein said sole comprises an outer sole and a midsole, said midsole having at least one recess defined therein, wherein said at least one air flow pump is located in said recess.
 7. Footwear as set forth in claim 6 wherein said midsole has a plurality of holes in the medial side and in the lateral side thereof, said holes being in registration with the open ends of the pump elements for communication of the pump elements with ambient air.
 8. Footwear as set forth in claim 7 wherein said holes in the midsole have a decorative shape.
 9. Footwear as set forth in claim 7 wherein said sole further comprises a liner, said liner having a plurality of openings therein, said openings in communication with the holes in the pump elements such that air can pass out of said holes and through said openings in the liner.
 10. Footwear as set forth in claim 2 wherein said pump elements are accordion-shaped in transverse cross section.
 11. Footwear as set forth in claim 2 wherein said pump elements are circular in transverse cross section.
 12. Footwear as set forth in claim 2 wherein said pump elements have enlarged portions to increase the size of said open ends.
 13. Footwear as set forth in claim 1 wherein said sole has heel, arch and forefoot sections, with air flow pumps being disposed in said arch and forefoot sections.
 14. Footwear having a ventilated sole system to cool a foot in the footwear, the footwear comprising: a generally horizontal sole having an outer sole and an insole providing a surface adjacent the foot; an air flow pump positioned between the outer sole and the insole, the air flow pump comprising a plurality of generally horizontal tubular pump elements extending generally transverse of the footwear from a medial side of the sole to a lateral side of the sole, each pump element defining an interior volume and having opposite ends open to ambient air, each pump element having a plurality of holes therein providing fluid communication between said interior volume and the surface adjacent the foot, and each pump element being resiliently compressible in a generally vertical direction upon impact of the footwear during walking or running and expansible upon liftoff, said resilient compression and expansion causing ambient air to flow through the holes in said pump elements to cool the foot.
 15. Footwear as set forth in claim 14 wherein said sole comprises a midsole between said outer sole and insole, said midsole having a recess therein, and wherein said air flow pump is located in said recess.
 16. Footwear as set forth in claim 15 wherein said midsole has a plurality of holes in sides thereof, said holes being in registration with the open ends of the pump elements for communication of the pump elements with ambient air.
 17. Footwear as set forth in claim 14 wherein said sole has heel, arch and forefoot sections, and said air flow pump is a first air flow pump, the footwear further comprising a second air flow pump, said air flow pumps being disposed in said arch and forefoot sections to cool the foot.
 18. Footwear as set forth in claim 17 further comprising a third air flow pump, said third air flow pump being disposed in said heel section to cool the foot.
 19. Footwear as set forth in claim 14 wherein said pump elements have enlarged portions to increase the size of said open ends.
 20. Footwear as set forth in claim 14 wherein the open ends of the pump elements are covered with a barrier pervious to the flow of air but substantially impervious to the flow of water. 